Gemini XPRIZE submission · built on the Google stack
Your heartbeat writes the soundtrack.
VO₂max.One reads your live heart rate, prescribes the session your physiology actually needs, and generates the music at that exact tempo. Every render is watermarked, disclosed and sealed.
- 5
- heart-rate zones
- 6
- phases per session
- 4
- public API endpoints
- 100%
- sessions hash-chained
How it works
Five steps, no guesswork
Your watch streams the beat
Apple Watch, Fitbit or any BLE chest strap. We read heart rate, HRV and cadence — never location, never audio.
Physiology becomes a prescription
Tanaka predicted max plus Karvonen heart-rate reserve gives a real target band, not a vibe. Six phases, one per stage of the session.
Music is generated at that tempo
Every phase gets a BPM anchor folded from your heart-rate target, so the track pulls you toward the zone instead of away from it.
The render is watermarked
Each track carries an inaudible payload tying audio to prescription and session, plus an AI disclosure a machine can read.
The record is sealed
Sessions land in an append-only, hash-chained ledger. Anyone can verify the chain without seeing your identity.
Why VO₂max
VO₂max is the strongest predictor we have
Maximal oxygen uptake tracks all-cause mortality more tightly than smoking status, blood pressure or cholesterol. Moving one fitness quintile is one of the largest modifiable effects in the literature — and the training that moves it is boring, repeatable zone work. Music is the adherence mechanism.
One number
VO₂max is the single best summary of how much oxygen your body can move and use per minute.
Modifiable
Zone 2 volume plus short intervals reliably raise it — the protocol is dull, not mysterious.
Measurable weekly
Field tests and resting heart rate track direction well enough to steer training.
Zone 1
Recovery
50–60% HRR
Blood flow and repair. Conversation stays effortless.
Zone 2
Aerobic base
60–70% HRR
Mitochondrial density and fat oxidation. The healthspan zone.
Zone 3
Tempo
70–80% HRR
Sustained power. Comfortably hard, speech in short phrases.
Zone 4
Threshold
80–90% HRR
Lactate clearance. Raises the ceiling you can hold.
Zone 5
VO₂max
90–100% HRR
Maximal oxygen uptake. Short, sharp, fully committed.
VO₂max calculator
Four protocols, one aerobic capacity number
Pick whichever test you can actually do today — resting pulse, a 1-mile walk, a 3-minute step test or a 1.5-mile time trial. Every method uses its published equation and rates you against the age-matched population average.
Read how each protocol is calculated. Calculating is open to everyone. Logging a result — the results card and your /history ledger — requires a signed-in account, because each logged run is sealed into your personal append-only hash chain and protected by row-level security.
No exercise. Count beats for 20 seconds at rest, add your age.
= 57 bpm
Uth et al. (2004) · Tanaka HRmax (2001). Estimate only — not a medical device and not a lab-measured VO₂max test. See the equation and error band.
Estimated VO₂max
48.7ml/kg/min
- Rating
- excellent
- Age-matched avg
- 37.8
- vs peers
- 1.29×
- Predicted HRmax
- 181 bpm
Login required: logged results are sealed into your append-only estimator ledger and shown on /history, which is also sign-in only. Calculating stays free and anonymous.
Turn this into a prescriptionLive estimator
Try it right now
No account needed. Drag your numbers, pick a workout, and get the real prescription with a Gemini coaching cue attached.
Step 1 · your numbers
entered manually
Don't know your VO₂max?
Uth–Sørensen non-exercise estimate · Tanaka HRmax — from age 38 and resting HR 58, estimated HRmax 181 bpm.
Sign in to seal estimator runs into your history trend.
Step 2 · device
Step 3 · today's workout
Step 4 · how you want to feel
Set your numbers and generate a prescription. Nothing is stored until you seal it.
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